Effect of surface treatments on the surface morphology, corrosion property, and antibacterial property of Ti-10Cu sintered alloy

Ti-10Cu sintered alloy has shown strong antibacterial properties against S. aureus and E. coli and good cell biocompatibility in vitro and in vivo, displaying potential application as an implant material. Surface treatments are always applied to implants to improve the surface biocompatibility. In this paper, several typically used surface treatments, including sandblasting (SB), sandblasted and large-grits acid etching (SLA), and alkaline heat treatment (AH) were chosen to modify the Ti-10Cu. A cp-Ti (commercially pure titanium) sample was used as control sample. The effect of surface treatments on the corrosion properties and antibacterial properties of the Ti-10Cu sintered alloy was investigated. After SB and SLA treatments, a rough surface with a TiO2 layer was formed on the surface, which reduced the corrosion resistance and enhanced the Ti and Cu ion release. After AH treatment, a smooth but microporous surface with a TiO2/titanate layer was formed, which improved slightly the corrosion resistance. However, the Cu ion and Ti ion release from the Ti-10Cu sample was promoted by AH treatment due to the fact that more Ti2Cu phases were exposed on the AH-treated Ti-10Cu sample. It was demonstrated that the Ti-10Cu samples after surface treatments still exhibited good antibacterial properties against S. aureus, which indicated that the surface treatment did not reduce the antibacterial activity. The control mechanism was thought to be related to the high Cu ion release even after surface treatments. It was expected that the surface treatments provided Ti-10Cu sintered alloy with good surface bioactivity without reduction in antibacterial activity.